Applicability and limits of the MGAU code for the determination of the enrichment of uranium samples

A new method for measuring the 235U enrichment in uranium samples has recently been developed based on the analysis of the 89 to 120 keV region of a gamma ray spectrum. The analysis process requires no calibrations and is capable of accuracies of 1–2% in measurement times of a few minutes, in favourable cases. s are presented for a variety of samples which show that in general good performance can be achieved. However, performance becomes poor when measuring uranium through thick walled containers. To partially overcome this problem, a new option has been tested which uses the intensities of the self-induced fluorescense X-rays of uranium. Initial results using this enhancements are encouraging.